kris/pqc
1
1
Fork 0
Code Issues Pull Requests Releases Wiki Activity

ct: adds chained memcmp test

Browse Source
This commit is contained in:
Henry Case 2021-06-30 23:40:09 +01:00
parent be7a0bbdb8
commit a2cd3fb88d
1 changed files with 27 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
test/ct.cpp
View File

@ -83,3 +83,30 @@ TEST(ConstantTime, CtCheck_memcmp) {
ct_purify(&ret, 1); ct_purify(&ret, 1);
ASSERT_EQ(ret,1); ASSERT_EQ(ret,1);
} }
TEST(ConstantTime, CtCheck_memcmp_chained) {
unsigned char a[16], b[16], c[16], d[16];
memset(a, 42, sizeof(a));
memset(b, 42, sizeof(b));
memset(d, 42, sizeof(b));
memset(c, 41, sizeof(c));
uint8_t ret;
ct_poison(a, 16);
ct_expect_umr();
// obviously must generate UMR if if first check fails
// and second is not done
ret = (ct_memcmp(a,c,16)==0) && (ct_memcmp(a,b,16)==0);
ct_require_umr();
ct_purify(&ret, 1);
ASSERT_EQ(ret,0);
ct_expect_umr();
// it's still UMR even if both checks are OK
ret = (ct_memcmp(a,d,16)==0) && (ct_memcmp(a,b,16)==0);
ct_require_umr();
ct_purify(&ret, 1);
ASSERT_EQ(ret,1);
}